The invention relates generally to a method and arrangement for the production of confectioneries. Of particular interest to the invention is the manufacture of high-boiled sweets such as hard caramel, low-boiled sweets such as soft caramel, jelly products and gum products.
In a known method for the manufacture of confectioneries, the ingredients are fed into a precooking machine in regulated quantities using a dosing device. Here, ingredients such as, for example, glucose syrup, which must themselves be manufactured by suitably combining and treating various constituents, are previously prepared and fed into the precooking machine in a prepared form. All of the ingredients in the precooking machine are mixed with one another solely by virtue of the small amount of turbulence which is generated by the precooking operation. The heating of the ingredients is effected indirectly by means of a heating jacket or coiled pipes arranged about the container in which the ingredients are accommodated. In this manner, the ingredients are heated to a maximum temperature of 110.degree. C. The precooked mass thus obtained is then pumped into a cooking machine and further heated to a temperature of about 140.degree. C. The energy for the heating is, as a rule, supplied via saturated steam. The cooking process may take place under vacuum. After reaching the just-mentioned final temperature of about 140.degree. C, the mass is dried to a residual moisture content of about 1 to 2 percent by weight with the aid of the vacuum and a condenser.
In the above-described method, as well in the other known methods to be described below, it is necessary to add approximately 20 percent by weight of water or moisture to the ingredients of the confectionery at the beginning of the production operation, that is, it is necessary to form a mass containing about 80 percent by weight of dry solids. The reason is that the design of the prior art apparatus is such that a satisfactory mixing of the ingredients cannot be assured with moisture contents of less than about 20 percent by weight. Depending upon the type of confectionery being manufactured, it may be necessary to demoisturize the mass of ingredients to a moisture content of 1.5 to 2 percent by weight at the end of the production process, that is, to a moisture content corresponding to about 98 to 98.5 percent by weight of dry matter. The process of demoisturizing, e.g. hard caramel, from 80 percent by weight of dry matter to between 98 and 98.5 percent by weight of dry matter is effected into stages and in two different apparatus.
In the method described above, the first demoisturizing stage is carried out in the precooking machine and involves a demoisturization from 80 percent by weight of dry matter to about 93 percent by weight of dry matter. The second stage of demoisturization is carried out in the vacuum cooking machine and involves a demoisturization from about 93 percent by weight of dry matter to between 98 and 98.5 percent by weight of dry matter.
A considerable disadvantage of the method outlined above resides in that a large quantity of water must be added to the ingredients. This is necessary not only to achieve an intimate mixing of all the ingredients as already mentioned but also for the dissolution of the sugar. Aside from these considerations, there is the further consideration that the mixing process utilized requires the mass of ingredients to have a relatively low viscosity. Thus, prior to the demoisturizing process, the percentage of dry matter is generally relatively low and, more particularly, has a value of only about 80 percent by weight. As a result, the demoisturizing process requires a relatively long period of time in comparison to the overall duration of the production process. Furthermore, the method outlined above is relatively complicated to carry out in practice since two apparatus are necessary, namely, a machine for the dissolution and precooking operations and a vacuum cooking machine. A further disadvantage of the abovedescribed method resides in that the indirect heating utilized leads to a poor thermal efficiency.
The method outlined above may today be considered as outmoded. On the other hand, another widely known method has come into being which, up to and including the precooking process, corresponds to the outmoded method described earlier. In this more modern method, the mass which leaves the precooking machine is conveyed into a buffer tank. From the buffer tank, the mass is pumped through a coiled pipe for cooking. The coiled pipe has a length of about 60 to 80 meters. In the coiled pipe, the precooked mass, which has been previously heated to a temperature of 110.degree. C, is indirectly heated with saturated stream in countercurrent flow to a temperature of 140.degree. C. Thereafter, the mass flows into a demoisturizing apparatus where the moisture remaining in the mass is removed together with the cooking vapors. In this method, the first demoisturization stage takes place in the precooking machine whereas the second demoisturization stage, that is, the demoisturization to the final moisture content, takes place in the demoisturizing apparatus.
Insofar as the temperatures, the moisture content, the proportion of dry matter and so on are concerned, the more modern method just described corresponds exactly to the older method outlined earlier. Since, in addition, this more modern method requires three separate machines, namely, a precooking machine, a coiled cooking pipe and a vaporizer or demoisturizing apparatus, the disadvantages set forth for the first method described are applicable to the second, more modern method also.
The most modern method today is the method according to the Ter Braak system. Here, the introduction of the ingredients is effected via the same dosing devices as in the two methods described previously. The ingredients are admitted into a premixing apparatus provided with a stirring device and a cold mixing of the ingredients is carried out in the premixing apparatus. The resulting charge is then conveyed into a storage and feed container which must likewise be provided with a stirring device in order to prevent settling of the still undissolved sugar crystals. From the storage and feed container, the sugar syrup solution is forwarded into an annular conduit by means of a conveying pump and is conveyed by individual cooking stations. The individual cooking stations are automatically fed from the annular conduit with the respective quantities of the solution required. It is possible to make use of so-called "rotor cookers". The stirring devices operate with a maximum rotational speed of 150 revolutions per minute.
This third method does not differ from the two previously described methods insofar as it process data are concerned. In this respect, then, the same disadvantages apply here as in the two other methods outlined. The only difference between the first two methods and the last method described resides in that the latter which, in principle, is the same as the other two methods, is carried out with different apparatus than either of the first two methods outlined. The development of this apparatus is obviously based on the recognition that the first two methods described are not well-suited for economical production. On the other hand, the apparatus used for carrying out the last method outlined again consists of a plurality of machines.